A Swiss army knife . . . essential in any survival situation. Photograph: Public Domain

Stuff. We have far too much of it in our lives, and we invest too much time, money and emotion accumulating it. This is not a modern-day revelation but one that was made 2,000 years ago by the prolific Roman author, Pliny the Elder. "An object in possession seldom retains the same charm that it had in pursuit," he wrote.

Wise words, but still we continue to consume as if our lives were one long clearance sale. In 2007, the US Consumer Electronics Association said that the average American owned 25 consumer electronics products and spent $1,200 each year buying these items. The five "most-owned" electrical items, it said, were the TV, the DVD player, the VCR, the cordless phone and the mobile phone. It's not a coincidence, therefore, that this decade has seen a boom in companies offering self-storage: we now own so much stuff to which we don't need regular access that we are willing to part with cash just to store it. We are buying empty space.

But how much of the stuff we buy do we really need? And how much of the stuff we already own do we really need to cling on to? People have been performing anti-consumerist purges of their worldly possessions since Henry David Thoreau wrote the seminal Walden in 1854, in which he recorded his two-year-and-two-month stay in a cabin in the Massachusetts woods living a "simple life". "A man is rich in proportion to the number of things which he can afford to let alone," he concluded.

It's no surprise to learn that Gandhi was greatly inspired by Thoreau's writings. It was said that the Indian leader could count his own possessions on two hands, and that they included his spectacles, pocket watch and sandals (all of which were bought at auction by an Indian millionaire earlier this year, for $1.8m).

Fast forward to today, and we can now buy the services of "declutter" life coaches, drop off a box of unwanted items on the doorstep of our local charity shop, or flog all our junk on eBay (so that someone else can own more stuff).

But there is also a growing band of clutter-busters, driven by a twin sense of environmentalism and anti-consumerism. Their logic is that buying a steady stream of tat not only helps to degrade the planet, but makes us unhappy.

An American blogger called Dave Bruno is attracting attention with his year-long experiment called the 100 Thing Challenge (guynameddave.com/100-thing-challenge.html). "The 100 Thing Challenge is my little way to personalise my efforts to fight consumerism," he says on his website. "I will live with only 100 personal things for one full year, until 12 November 2009."

It sounds like an interesting experiment in self-discipline and self-discovery – until you read the many conditions and clauses he has introduced into the small print: "Clearly family-shared and household things (eg, dining room table, piano, bed, plates etc) are not considered a personal thing," he declares.

More controversial, perhaps, is his decision to group certain items so they can be counted as "one item": "This includes underwear and socks. I'm not keeping a lot of either. We do, though, run a household. The idea of trying to manage laundry with a few pairs of skivvies and socks is both unrealistic and gross."

Bruno is also allowing himself to buy new items so long as his total number of possessions does not exceed 100 items. And he is allowing himself access to some household tools such as a hammer, screwdriver and tape measure. His justification? "Just last week I needed some tools to put up my daughter's gymnastics bar."

So, with a few carefully chosen exemptions, the 100 Thing Challenge has suddenly become the "238 (Or Something In That Ballpark) Thing Challenge". Not so impressive. And when you look at his list, it doesn't look like he is stretching himself in the way Thoreau or Gandhi did. He has, after all, kept his business casual cords, surfboard, Patagonia wrinkle-free button-down shirt and side table. (Interesting choices, given that he has let go of his self-portrait oil painting, magnesium fire-starter stick and Canon 30D camera.)

I'm beginning to sense that a proper challenge for the modern consumerist should be bolder than Bruno's. That's to say, live for a year with just 10 possessions. But what would I choose? (Leo's small print: I'm not including basic items of clothing – shirt, a pair of trousers, underwear, T-shirt, coat, pair of shoes – nor am I including the basic, shared utensils, furniture, appliances and sundries you would find in most homes – chair, bed, saucepan, knife and fork, towel, loo roll, cooker, fridge etc.)

Swiss army penknife

Always the first item to go into the suitcase. Not only does it allow you to open a tin of beans or change the fuse in a plug, but it also lets you pull a stone from a horse's hoof and a thorn from your thumb. Essential in any survival situation.

Mobile phone

Yes, we all managed to live with them only a decade or so ago – I believe geologists now refer to it as the Pre-Mobilian Age – but could I really survive without one now? Doubtful. Also, just think of all the other applications they boast. Especially once you factor in the built-in camera, calculator, alarm clock, email etc.

Cotton buds

Seriously, I think I could survive longer without water and sleep than without cotton buds.

Toothbrush

I would forgo a razor. I would even forgo deodorant if I really had to. But the thought of living without a toothbrush for a year is just too much (and no, I won't consider using a twig to brush my teeth).

Laptop

We are lucky enough to live in an age when we can put our entire music collection, book shelf and family photos on to one hard drive. An internet-enabled laptop also lets you conduct internet searches, watch TV/DVDs and buy stuff (oh, I can't do that now, can I). This allows me to avoid the tortuous Desert Island Disc-type decision-making about which albums or books to pick. Dave Bruno affords himself no less than three Bibles in his list of 100 items.

Umbrella

I live in Cornwall. I shouldn't need to explain myself.

A pen

Even though I have my laptop, I would hate not to be able to write anything down.

A diary

I'm hopeless at organising my life and just can't seem to get on with the electronic organisers found on mobile phones and computers. Therefore, I need a day-to-view A4 desk diary.

Child's painting

One of the greatest dilemmas facing any parent is whether or not to throw away a picture that your child has lovingly painted or drawn for you. Of course you should keep them all, but how are you realistically expected to cling on to all those endless bundlesof them for ever more? A heart-rending choice, but I can keep only one.

Prince's plectrum

I'm a shameless Prince fan, and I would rather rub swine flu in my eyes than be forced to give up the plectrum the world's greatest performer handed to me during a gig when I was 14 years old. This, then, is my most treasured possession of all.

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